<template>
   <div>
      <div style="display: inline-block" v-for="(item, index) in arr" :key="index">
         <input type="checkbox" :value="item" v-model="num"/>
         <span>{{ item }}</span>
      </div>
      <p>你选中的元素, 累加的值和为: {{ sum }}</p>
   </div>
</template>

<script>
export default {
  data() {
    return {
      arr: [9, 15, 19, 25, 29, 31, 48, 57, 62, 79, 87],
      num: []
    };
  },
  computed: {
      sum () {
         return this.num.reduce((prev, item) => prev + item, 0)
      }
  }

};
</script>

<style>
</style>